Detachable self locking driving device



Sept. .3, 1957 w. F. FLETCHER DETACHABLE SELF LOCKING DRIVING DEVICE Filed Sept. 7-, 1954 Utliifi DETACHABLE SELF LOCKING DRIVING DEVICE Application September 7, 1954, Serial No. 454,315

3 Claims. (Cl. 279--9) This invention relates to improvements in detachable self locking driving devices for drills and the like and more particularly relates to an improved form of self locking grip socket and quill particularly adapted for mining drills.

The practice has developed in recent years of supporting mine roofs in coal mining operations, by roof plates bolted to the roof by expansion bolts insertable in vertical holes drilled in the roof. This requires relatively deep holes in order to provide adequate support for the roof bolts, necessitating the use of long drills, and in many cases a series of successive drilling operations.

In order to drill such holes in the roof, the drilling head is usually guided in vertical guides and rests on the ground when initially starting the drilling operation, the drill being aligned by an aligning guide spaced vertically from the drill head. Oftentimes the bit is spaced States Patent the walls of the socket of which are in the form of the frustum of a pyramid with the base at the inner end of the socket, and the Walls of the quill of which are of a similar form with the base at the outer end of the quill and looking with the walls of the socket upon rotation thereof.

A still further object of my invention is to provide a self locking drive device comprising a quill and socket having plain interengaging side walls tapering to provide an interlocking connection between the quill and socket, and so constructed and arranged as to be readily attachable and detachable and be compatible and interchangeable with the common sockets and quills now in use.

These and other objects of my invention will appear from time to time as the following specification proceeds and with reference to the accompanying drawings wherein:

Figure 1 is a fragmentary view in side elevation of a mining drilling apparatus showing a drilling head positioned adjacent the ground, and a vertically extending drill steel driven thereby through a detachable driving device constructed in accordance with my invention;

Figure 2 is an enlarged detail view in side elevation of the driving device of my invention;

Figure 3 is an exploded view of the driving device shown in Figure 2; and

Figure 4 is the transverse sectional view taken substantially along the lines IV-IV of Figure 2.

from the roof and travels before the hole is started with the result that the bit is frequently misaligned with the drilling head even where a drill guide is provided, necessitating a loose fit between the drill steel and its socket and a rather shallow socket.

With such sockets, when lowering the drill head to remove the drill, the frictional grip between the drill steel and socket will be insufficient to withdraw the drill steel with the socket, and the drill and socket will come apart, necessitating the withdrawing of the drill by hand.

It is therefore, a principal object of my invention to provide a self locking detachable driving device particularly adapted for mining drills, which is so formed as to provide a self locking drive connection, positively withdrawing upon rotatable withdrawing movement of the driving device.

Another object of my invention is to provide a detachable driving device or chuck particularly adapted for mining drills and comprising a mating quill and socket, the mating surfaces of which are so tapered as to provide a ready insertable self locking drive connection preventing separation of the quill from the socket upon rotation of the socket in either a drilling or withdrawing direction.

A still further object of my invention is to provide a chuck or drill socket for mining drills and like tools in which the contact surfaces are relatively broad, to increase the life thereof and to enable ready attachment of a drill steel or tool and provide a self aligning and locking driving device.

A still further object of my invention is to provide a socket and quill for mining drills in which the socket has plain angular side walls tapering outwardly from the outer to the inner end of the socket and in which the quill has a male shank having side walls corresponding to the side walls of the socket and tapering inwardly from the outer to the inner end of the shank, to efiect positive gripping of the quill with the socket upon rotation of the socket and withdrawal of the socket as long as the socket is rotating.

A still further object of my invention is to provide a quill and socket particularly adapted for mining drills,

In Figure l of the drawing I have diagrammatically illustrated a drilling apparatus of a type similar to that shown and described in my joint application with James R. Fletcher, Serial No. 321,344 filed November 19, 1952 and entitled Mobile Roof Drill and shown herein in order to illustrate the adaptation of my invention to a mining drill, and of itself no part of my present invention except insofar as the detachable driving device of my invention is connected thereto and driven thereby.

The drilling apparatus, as shown in Figure 1, is in the form of a wheel mounted truck 11 having extensible vertical guides 12 at the forward end thereof, along which is guided a drilling head 13.

The drilling head 13 may be of a well known form having a motor 14 for driving a socket member 15 of the self locking driving device of my invention in a well known manner, so not herein shown or described further. The driving device also includes a quill 16 having interengagement with the socket 15 and having a drill steel 17 secured thereto. e

The drill steel 17 is shown as extending vertically from the quill 16 through an aligning guide 19 supported at the upper end of the guides 12 and movable therewith during upward feeding movement of the drilling head 13. The drill steel 17 may be slotted at its upper end and have the usual bit (not shown) attached to the slotted portion thereof.

Referring now in detail to the socket member 15 and quill 16 forming the self locking detachable driving device of my invention, and Figures 2, 3 and 4 in particular, the socket member 15 is shown as being generally cylindrical in form and having plane upper and lower faces 21 and 22 respectively. A socket 23 is provided in the lower end of the socket member 15 through the lower face 22 thereof. The socket 23 may be threaded and may be held in the drill head by means of a bolt or the like (not shown) threaded therein or which may engage a male drive member (not shown) driven by the drill head for driving the socket member 15, in a manner well known to those skilled in the art, so not shown herein or described in detail.

The face 21 of the socket member 15 is shown as having a socket 24 extending inwardly therefrom, to be engaged by a shank 25 of the quill 16.

The opposite face of the quill 16 from the shank 25 Patented Sept. 3, 1957 is shown as having a socket 26 formed therein for receiving a tool or drill steel 17, which may be connected thereto as by a pin or rivet 27 extending through a countersunk cross drilled portion 29 thereof, and riveted thereto.

The socket 24 is shown as having plain side walls 30, forming a polygon in the form or a square in cross section. The side walls 36 are shown as tapering outwardly from the outer to the inner end of the socket and as forming a frustum of a pyramid, the base of which is at the bottom of the socket. It is, of course, understood that the socket 24 need not be square or in the form of the frustum of a pyramid, but may be of various other forms desired as long as at least one Wallis plane.

The shank 25 is likewise shown as having plane side walls 31 forming a polygon or square in cross section and tapering inwardly from the outer to the inner end of the shank at the same angle as the angle of taper of the side walls 39 of the socket 24 and forming the frustum of a pyramid, the base of which is at the outer end of the shank. The perimeter of the outer end of the shank 25 is slightly smaller than the perimeter of the socket 24 at the face 21, so as to accommodate the shank 25 to be readily placed in the socket 24 and inserted therein for the full depth thereof.

It may be seen with the reference to Figure 4, showing the relationship between the socket 24 and shank 25 in a slightly exaggerated form, that upon turning movement of the socket member 15, the tapering side Walls 30 of the socket 24 will first twist and engage the side walls 31 of the shank 25, adjacent the corners of the socket. This will offset the socket with respect to the shank and the oppositely acting torsion forces on'the shank and socket will lock the shank 25 to the socket 24 by the taper of the side walls thereof, as long as the socket is rotating to drive the shank. The socket 24 may thus positively Withdraw the drill 17 from the mine roof or face as the socket is rotated and moving away from the roof or face.

It may be seen from the foregoing that I have provided a self locking driving device in which two members are retained in connected relationship only while the two members are under torque action, and that this connected relationship is maintained for any depth of penetration of the shank with respect to its drive socket.

It may further be seen that the connection between the socket and shank may be relatively loose so as to permit limited angular movement of the quill and drill with respect to the socket and thus provide a self aligning driveconnection and eliminate localized bending stresses in the drill steel.

It may also be seen that the engaging surfaces of the drill and shank are sufficiently wide to provide long wearing drive surfaces, giving long life to the socket and quill and enabling ready insertion in and removal of the drill and quill from the socket.

It will be understood that modifications and variations in the present invention may be effected without departing from the spirit and scope of thenovel concepts thereof.

I claim as my invention:

1. A self locking detachable driving device comprising a driven socket member, a driving quill having interengagement therewith and driven thereby, said socket member having a socket formed therein opening to one face thereof having at least one plane side wall tapering outwardly from the outer t0 the inner end thereof and said quill having a shank engageable with said socket and having at least one plane tapering side wall tapering inwardly from the outer to the inner end thereof in generally parallel relation to the tapering side wall of said socket, and the perimeter of said shank at its outer end being less than the perimeter of said socket to accommodate free insertion of said shank within said socket.

2. A self locking detachable driving device comprising a driven socket member, a driving quill having interengagement therewith and driven thereby, said socket member having 'a socket formed therein opening to one face thereof and in the form of the frustum of a pyramid the base of which is at the inner end of the socket, and said quill having a shank projecting therefrom for engagement with said socket and in the form of the frustum of a pyramid the base of which is at the outer end of said shank and is engageable Within said socket.

3. A detachable self locking driving device particularly adapted for mining drills and the like, comprising a socket member adapted to be rotatably driven by a mining head, a quill 'interengagea'ble with said socket member and adapted to have a drill and the like detachably secured thereto, said'socket member having a socket therein having plane side walls tapering outwardly from the outer to the inner end of said socket and said quill having a shank registerable with said socket and having plane side walls tapering inwardly from the outer to the inner end of said shank and of the same general form as the form of the side walls of said socket.

References Cited in the file of this patent UNITED STATES PATENTS 350,860 Baldwin Oct. 12, 1886 1,032,492 Mueller July 16, 1912 1,355,793 Bernay Oct. 12,- 1920 

